The use of aqueous alkyl methacrylate and alkyl acrylate ester polymers as printing ink vehicles, overprint varnishes and lacquers is generally known in the art. However, several problems still exist, for example heat resistance of the dried films is low. Heat resistance is needed for many applications in inks and overprint varnishes. A major use is for printing preprint linerboard, where a high degree of hot rub resistance is needed. Another significant use is heat sealing of foil to form airtight seals (metallized balloons, coffee pouches, etc). Overprints are often used in preprint and some heat seal applications as a protective coating over standard inks. It is known that heat resistance can be improved by adding large quantities (about 4-10 wt. %) of zinc compounds such as zinc oxide or zinc ammonium carbonate (ZAC). However, the high pH of these zinc compounds leads to strong ammonia smell and large amounts of zinc can be toxic.